JPS61151035A - Semiconductive glass - Google Patents

Abstract

PURPOSE:To provide a semiconductive glass useful as an electrode material of parallel-plate local discharge counter, etc., by adding one or more compounds selected from MgO, SrO and BaO as essential components to a specific composition composed of SiO2, CaO and Fe2O3. CONSTITUTION:The objective semiconductive glass is composed of 25-50(wt)% SiO2, 1-36% CaO, 0-12% MgO, 0-17% SrO, 0-40% BaO (MgO+SrO+BaO =5-48%), 10-32% Fe2O3, 0-20% PbO, 0-12% Sb2O3 and 0-12% TiO2.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention uses S+02, CaO, (MgO
.

containing one or more components of SrO and BaO) and Fe2O3, and a parallel plate local discharge counter (Planar 5p
The present invention relates to a semiconducting glass suitable for use as an electrode material for ARK counters.

The above-mentioned discharge counter is a device for measuring the momentum of charged particles such as cosmic rays, and usually uses a cathode made of vacuum-deposited copper on the surface of a float glass plate and a plate-shaped semiconducting material. Two sets of parallel plate electrodes are prepared in which the electrodes are opposed to the anode in parallel with a gap of about 100 to 200 go+, and these are arranged facing each other with an interval of about 2 m. For measurement, in advance, 3
A predetermined high electric field in the range of 00 to Boo KV/c is applied, and charged particles are passed through the above two sets of parallel plate electrodes one after another. By extracting the spark signal and measuring the time interval, the momentum of the charged particle is measured.

In general, the anode materials for discharge counters as mentioned above are:
Attempts have been made to use semiconducting glass, but the following requirements are required.

(1) Volume specific resistance is approximately 10-1011Ω・can't
'Yes, and the desired value within the above range can be stably obtained.

(2) There is no aging deterioration of volume resistivity.

(3) Excellent chemical durability.

(4) Striae and bubbles throughout the large plate-like body.

It should be homogeneous with no devitrification etc. (If these defects exist, the uniformity of volume resistivity will be lost or unnecessary sparks will be induced, causing measurement errors.) (5) Hot formability and polishing workability It has excellent properties and can manufacture large plate-shaped bodies.

(6) Not expensive.

(B) Prior Art Conventionally, various types of semiconducting glass having a volume resistivity of about 10 9 to 10 11 ΩAC11 have been known. However, when used as the electrode material, for example,
AgPO3-Al(PO3)3-V2O5 glass not only has poor chemical durability, but also has disadvantages in terms of raw material economy.
2-Na2O-Fe3O4 system and 5i02-PbO-B
Glasses such as i203-alkali metal oxide have disadvantages in that alkali ions gather on the surface under the influence of a high electric field, inducing unnecessary sparks and changing volume resistivity.

In addition, 3-component glasses of S+02, CaO and Fe2O3 and 3-component glasses of S+02, BaO and Fe2O3 are also known, but the former cannot be stabilized against devitrification by normal melting methods in the air. Very bad sex,
Furthermore, since the latter have poor chemical durability, neither of them can meet the above requirements.

()\) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned circumstances, and its purpose is to be suitable for use in anode materials for parallel plate local discharge counters, etc. The object of the present invention is to provide a semiconducting glass with a novel composition.

(d) Means for Solving the Problems In order to achieve the above object, the present inventor has conducted extensive testing and research and found that, in addition to each component of SiO□, GaO and Fe2O3, The present inventors have discovered that a semiconducting glass that can comprehensively satisfy the above requirements can be obtained in a composition system containing one or more species as essential components, and have thus come to form the present invention. That is, the characteristics of the semiconducting glass according to the present invention are, in weight percent, 5i0225-50%, CaO 1-36%, MgO,
Total amount of one or more of SrO and Ban 5 to 4
8% (however, 8g0O~12%, SrO0~17%,
BaO 0~40%), Fe2O31G~32%,
Pb00-20%, Sb2O30-12% and Ti0
The content is between 70% and 12%.

Next, the reason for limiting the composition range of each component as described above will be described.

The SiO□ component contains a large amount of F as a conductive component in the glass.
It is an effective component to contain e2O3 and improve the chemical durability of glass, but if the amount is less than 25%, the tendency of glass to devitrify increases, and if it exceeds 50%, the melting temperature will decrease. This makes it difficult to obtain glass free of bubbles and undissolved substances.

In the present invention, the CaO component improves the chemical durability, hot formability, and polishing workability of the glass, and as described later, the CaO component promotes melting in place of the alkali metal oxide, which should be contained in a low content or without additives. Since it is effective as a drug, it is considered an essential ingredient. The above effect is produced when the amount of CaO is 1% or more, and it is more effective when it is 5% or more, so it is preferable, but when it exceeds 36%, the tendency to devitrify increases.

In the present invention, if the glass contains only CaO as the alkaline earth metal oxide component, the glass tends to tend to devitrify, but MgO1SrO and Ba
When each component of O coexists with the CaO component, defoaming during melting is further promoted, and stability against devitrification can be improved while maintaining good chemical durability. Therefore, these components are important components in the present invention, but if the total amount of one or more of these components is less than 5%, the coexistence effect will be insufficient, and if the total amount of one or more of these components is less than 5%, the coexistence effect will be insufficient.
Exceeding this value actually increases the tendency for devitrification. However, Mg
Each component of O, SrO and BaO was 12% and 1%, respectively.
If it exceeds 7% or 40%, devitrification tends to occur, which is not preferable.

The Fe2O3 component is a conductive oxide with excellent raw material economy, but if its amount is less than 10%, it will not be possible to obtain a glass with the desired volume resistivity, and if it exceeds 32%, the glass will undergo a phase separation phenomenon. occurs, making it impossible to obtain a homogeneous glass.

The following components are not essential for the glass of the present invention, but they have the effect of improving the viscosity and conductivity of the glass, so
Can be used as needed.

That is, PbO and Sb2O3 are effective components for lowering the viscosity and melting temperature of glass, but their effects can be fully exhibited at amounts of 20% and 12% or less, respectively. When used in combination with the Fe2O3 component, the TiO2 component has the effect of increasing the electrical conductivity of the glass, but if used in a large amount, the glass tends to devitrify, so it is preferably 12% or less.

In addition, the glass of the present invention may optionally contain, in addition to the above components,
Small amounts of B2O3, Al2O3, Y2O3, La2O3,
Gd2O3, C; e02.5n02, ZrO2, Nb2
O5, Ta205, ZnO, WO3, As2O3, V2
O5, Cr2O3, Co2O3.

One or more components such as Mo2O3, Bi2O3, MnO2, NiO, CuO, and F can be contained up to about 5% in content. In addition, in order to lower the volume resistivity of glass and further improve its melting properties, alkali metal oxides can be added to the glass in an amount of about 2% or 2%, but when used as the anode material, the above-mentioned drawbacks arise. Preferably, it is substantially alkali-free.

(E) Example Next, Table 1 shows an example of the composition of the semiconducting glass according to the present invention and the measurement results of the volume resistivity (ρ) of the obtained glass at 25°C.

The glass of the practical composition example was prepared in accordance with a normal optical glass manufacturing method by preparing blended raw materials consisting of oxides, carbonates, nitrates, peroxides, etc. in an oxidizing atmosphere in an electric furnace or gas furnace. After melting at 1000-1250°C and homogenizing by removing bubbles and stirring,
It can be easily manufactured by lowering the temperature to a temperature of 100 mL, casting it into a mold, and slowly cooling it.

As seen in Table 1, the crow of the composition example of the present invention has a volume resistivity ranging from about 10 to 1O11Ω·Cl11. These glasses.

During production, the desired volume resistivity can be stably obtained with good reproducibility without being affected by melting time, and since it is alkali-free, the obtained volume resistivity does not deteriorate over time. , chemical durability is also good. Furthermore, these glasses are free of striae, bubbles, devitrification, etc., have excellent homogeneity, and have good hot formability and polishing workability.
Therefore, the required electrode material for a parallel plate local discharge counter is, for example, a thickness of 0.3 cm, a width of 10 cm, and a length of 100 cm.
It is possible to stably manufacture large, homogeneous products of up to m.

(f) Effects of the Invention As described above, the semiconducting glass of the present invention has a specific composition range of ・5i02-GaO-(MgO, SrO and B
Since it is a -Fe2O3-based glass (component of one or more -F), it is possible to stably obtain a desired volume resistivity in the range of about 10 to 1011Ω・0 layer, and the obtained volume resistivity It does not deteriorate over time and has excellent chemical durability. In addition, the semiconducting glass of the present invention can be easily homogenized during the melting process, and has excellent hot formability and polishing processability, so it is possible to manufacture large-sized products with high yield. It also has excellent raw material economy. Therefore, the semiconducting glass of the present invention can be used not only as a large-sized material as required for the electrodes of parallel plate type local discharge counters, but also as a semiconducting material for various other uses. Therefore, it is extremely useful industrially.

Claims (1)

[Claims] In weight%, SiO_225-50%, CaO1-36%
, MgO, SrO and BaO, the total amount of one or more of them is 5-48% (however, MgO 0-12%, SrO 0-48%)
17%, BaO0-40%), Fe_2O_310-3
2% of PbO, 0 to 20% of PbO, 30 to 12% of Sb_2O, and 20 to 12% of TiO.